Oil burner



July 30, 1940- w. H. FRANKLAND OIL BURNER Filed May 26, 1958 gwum vhwWfi fiankland Patented July 30, 1940 UNITED STATES PATENT OFFICE- 4Claims.

This invention relates to oil burners in general, and more particularlyto oil burners installed in radiant heaters of a type used in theheating of. small homes and apartments.

One of the most efflcient types of these oil burning heaters includes avertical heat radiating combustion chamber enclosed in a casing and incommunication with an oil containing receptacleat its lower end. A downdraft tube depending from the top of the chamber coaxial with saidreceptacle and terminating a short distance from the upper end thereof,serves to spread the flame resulting from the burning of the oil in saidreceptacle and to provide the air necessary to ensure completecombustion of gases generated by the burning oil. Even with thiseiilcient type of burner, it has been found that the starting operationcan be greatly accelerated by arranging a starting tube concentric withthe down draft tube and extending through the opening in the oilreceptacle to a short distance above the surface of the oil in thebottom of the oil receptacle.

It has been customary in starting these heaters,

without the use of a starting tube, to open the door with which thecombustion chamber is provided and drop lighted matches, one afteranother, onto the oil in the oil receptacle until the oil becomesignited and the flame spreads into the combustion chamber. Thisoperation is time consuming and has a tendency to form carbon within theoil receptacle during the period required by the matches to heat the airand oil vapor within the receptacle to its flash point,

or to the temperature at which this mixture of air and oil vapor burnscontinuously.

It is the primary object of this invention to provide the type of heaterjust referred to with means whereby the oil in the receptacle may becaused to ignite a great deal more readily than has been possibleheretofore; and thereby to eliminate practically all possibility i offorming carbon in the oil receptacle.

Other objects of the invention will become apparent as the detaileddescription thereof proceeds.

In the drawing:

Figure 1 is a central vertical section through a down draft oil-burningheater provided with the starting tube which forms an essential elementof the present invention;

Figure 2 is a horizontal section, taken on the line 2-2 of Figure 1; and

Figure 3 is a fragmentary section showing a 5 modified form of theinvention.

As shown in the drawing, the invention comprises a casing 4, which maybe more or less ornamental, provided with a top 5 having apertures 6through which heated air escapes into a room or apartment to be heated.The casing 4, 5 provided with a bottom I, is. mounted on a base 8, partof which is cut away to form a recess 9 through which air may be drawnfor the purpose of ensuring combustion of the fuel oil in the heater.The casing 4 has one wall thereof 10 provided with a door in which maybe swung about its hinges H to give access to a heat radiatingcombustion chamber I! mounted concentrically within the casing 4.

The heat radiating chamber l2, closed at its 15 lower end by a bottom l3and at its upper end by a cover I4, is supported on the upper end of anouter receptacle l5, within which is mounted an oil-receiving receptacleit connected to a perforated cylindrical shell H. The bottom 1 of 20 thecasing 4 and the bottom of the outer receptacle 15, are provided withregistering apertures i8 and 69, respectively, to provide a passage forthe air necessary to ensure combustion of oil in the receptacle IE. 5

The bottom i3 is provided with an upturned nozzle 20 for the oil vaporundergoing combustion. A down draft tube 2|, suspended from the top H ofthe combustion chamber l2 coaxial with the shell l1 and the nozzle 20,terminates 30 a short distance above the upper end of said nozzle 20,and has its lower end provided with a series of apertures 22 throughwhich air may be drawn to spread the flame issuing from the nozzle 20. Aflue 23, extending through a wall of 35 the combustion chamber i2 andthe outer casing 4, conducts the exhaust products of comlligstion awayfrom the heat radiating chamber The open upper end of the down drafttube 2| extends through the cover H. The starter tube 24 extendscoaxially with the down draft tube 2! through the combustion chamber 12and through the shell ll to a point slightly above the pool P of oilintroduced into the receptacle for the purpose of starting the heater inoperation. The starter tube 24 is adjustably supported, preferably byfriction fit, in an apertured spider 25 suitably secured to the top H ofthe combustion chamber !2; and a cap 26 is detachably secured 50 to theupper end of the starter tube 24 to close the same after the burner hasbeen properly set in operation.

It is not absolut ly necessary that this starter tube 24 should extendthrough the down draft tube 26. A substantial equivalent of the tube 24comprises a tube 2? extending through the casings 4 and I2 and bent toform a branch 28 extending downwardly and concentrically through thenozzle 20 to a point close to the surface of the pool of oil introducedinto the receptacle l6 for starting purposes through a valvecontrolledpipe 29. The outer end of the tube 2? may be provided with a suitableclosure valve as to cut off the supply of air after the oil in theburner has been properly ignited. The wall of the chamber l2 opposite tothe door it of the outer casing i is also provided with a door 38through which matches or the like may be introduced or thrown throughthe nozzle 2@ for the purpose of igniting the oil within theoil'receptacle E6.

' Without the starter tube, it is usually necessary to throw four orfive matches into the burner receptacle before the fuel oil vaporbecomes ignited. Fuel oil, when admitted first to the bottom of theburner, forms a shallow layer, or pool. It is believed that thedifficulty -of ignition is due to the fact that the atmosphere close tothe surface of the oil is diluted by oil vapor and lacks suflicientoxygen to start ignition of the vapor. By providing a starter tube incommunication at one end with the atmosphere and having its other endclose to the surface of the fuel oil, it has been found that the firstmatch thrown into the burner usually starts ignition of the fuel oil.This quick starting naturally prevents formation of carbon withintheburner and adds to the effectiveness of the heater as a whole. Justas soon as ignition has begun, the cap on the outer end of the startershould be closed, because the down draft tube supplies all the airnecessary to spread the flame and ensure complete combustion.

The burner, including the liquid oil receptacle l6 and the aperturedshell iii, are of standard construction in many modern fuel oil heaters;and is a type of burner used to some degree in practically all fuel oilheaters manufactured and sold at the present time. This burner is veryefficient and produces a clean and carbonless flame; but, as is the casewith all such burners, it is very slow and diflicult to light. The airholes in the shell I! are designed to allow only sufllcient air to enterthe burner and mix with the oil gases when the burner is hot andproperly operating as a heater. However, these air holes are notsufiicient to permit the necessary amount of air to come in contact withthe starting supply of liquid oil in the receptacle part of the burnerto ensure quick starting. If these holes were sufficient in size andnumber to make the burner easy to light, they would keep the burner fromoperating effectively when the burner becomes hot, and would cause avery hard carbon due to excess of air in the burner.

It will be noted, from Figure 1 of the drawing, that the bottom row ofholes in the shell I 'I is located above the top ofthe receptacle l6 andabove the inlet end of the tube 2|. This arrangement is necessarybecause the underwriters require that the liquid fuel receptacle be ofsuch depth as to provide a certain liquid level which is determined bythe usual float valve control with which all fuel oil heaters areprovided and which automatically cut off the flow of oil into thereceptacle in case the heater is turned on and not lighted. Inconsequence of this construction' of the modern oil heater, theatmosphere close to the surface of the normal starting supply of liquidoil in the receptacle I6 becomes diluted with oil vapor and lackssufficient oxygen to start ready ignition. By arranging the starter tubewith its inner end below the lowermost row of apertures in the shell ll,oxygen from the atmosphere is brought down close to the surface of thenormal starting supply of liquid fuel in the receptacle.

The draft of the flue to which the stove is attached causes a suction ofair, whether the heater is lighted or not, and this suction draws theair down the starter tube, when opened at its outer end, onto thestarting supply of liquid oil at the surface thereof. When the oil islighted, this tube provides a sufficient amount of oxygen to ensurequick lighting at a point close to the surface of the normal startingsupply of liquid fuel, which is not present in the modern type burnersnow used. The rush of air down the starter tube fans the flame,resulting from the throwing of a lighted match onto the liquid fuel,into a very hot flre which causes the burner to become hot enough withina period of a minute and one half to two minutes to effect theichange ofthe oil into gas, a process which ordinarily takes from :welve to twentyminutes in burners of the usual ype.

While the starter tube is shown in Figure 1 of the drawing as passingthrough the down draft tube of the heater, it has no effect whatever onthe operation of this down draft tube. The sole purpose of the presentinvention is to provide a tube adapted to be suitably mounted on astandard radiant oil heater so as to decrease materially the timerequired for starting the heater into operation.

While I have illustrated the apparatus for carrying out this method asembodied in a par-' ticular form, it is to be understood that it is notto be considered as limited to that form or in any other manner exceptas indicated by the scope of the claims appended hereto.

What I claim is:

1. Radiant heater including in combination, a casing open to atmosphere,means within said casing and spaced therefrom forming a radiatingchamber, a pot-type burner within said casing having an open top incommunication with said radiating chamber, said burner being providedwith lateral air passages communicating with said casing, and beingprovided with a liquid fuel inlet adjacent its bottom, a down draft pipeextending into said radiating chamber and opening within said casing,and having its lower open end terminating adjacent to but above the topof said burner, and a starting air tube having its upper end open toatmosphere, having its lower portion extending into said burnercoaxially with said down draft pipe, and having its lower open endterminating below said lateral air passages and adjacent the bottom ofsaid burner.

2. In combination, a liquid fuel heater having means forming a radiatingchamber, and an oil burner below said radiating chamber with a partitiontherebetween having a narrow throat affording communication between saidoil burner and said radiating chamber;- said oil burner including areceptacle adapted to contain a normal starting supply of fuel oil, andhaving a surrounding shield defining a precombustion space above saidreceptacle, a starting tube extending through said radiating chamberinto said precombustion space and terminating slightly above the planeof the normal oil level in said receptacle, the other end of saidstarting tube being in communication with atmosphere. a closure for saidlast mentioned end, the starting tube having its inner end portionexposed to the precombustion space and the adjacent portion oi. saidradiating chamber, and means within said radiating chamber shielding theupper portion of said starting tube.

3. Liquid fuel heater as claimed in claim 2, said shielding meanscomprising a tube terminating above said throat and open at its oppositeend to atmosphere, constituting the air tube for supplying air fornormal combustion after starting.

4. Liquid fuel heater as claimed in claim 2, 5 and including means foradjusting said starting tube toward and from the surface of thestartingsupply 01' fuel oil.

WILLIAM HOWARD FRANKLAND.

